Expert Boiler Installation Guide: New Boiler Cost Explained in Detail

Looking for a new boiler? There’s a good chance you’re confused by all the options. That’s why we did the hard work and put together this expert boiler installation guide on new boiler costs in 2022.

After all, there are several boiler types and sizes, dozens of brands, hundreds of models, plus an array of installers (all of whom claim to be the best and cheapest). All of these factors determine the cost of buying a new boiler for your home.

New boiler costs

So, which boiler size, type, brand, and model do you choose? And whom should you hire for installation to keep the cost of the new boiler low?

This guide covers everything you need to know before buying a new boiler. We’ve even included a boiler replacement cost comparison guide (with ACTUAL quotes we received), showing back-to-back prices from the likes of British Gas, Heatable, and Help-Link.

Combi Boiler Deals From Heatable

In a hurry and not enough time to read the full guide? No problem. Simply fill out a quick form from Heatable and get a fixed boiler quote in 2 minutes.

How Much Does It Cost to Install a New Boiler?

There are tonnes of factors that affect the cost of installing a new boiler, but here are a few of the most common ones:

  • The boiler type that suits your property best
  • The fuel your boiler uses (an oil boiler will typically costs more than its gas counterpart)
  • Whether or not you have to move your replacement boiler into a new spot
  • Which installer you choose to supply the boiler and perform the work

With this many variables, it’s difficult for me to tell you precisely how much your boiler installation will cost. If you want to get a quick, fixed quote yourself, you can use this online boiler quote calculator and see what Heatable offers you.

That said, I did prepare a table summarising average national boiler replacement costs across the UK. These are based on reputable boiler brands in the 24kW-30kW range.

Work requiredBoiler TypeCost
Replace boiler, using the existing locationRegular£1,900
Replace boiler, moving to a new locationRegular£2,350
Central heating system upgrade to a combination boiler (including removal of hot water tanks)Regular£2,850
Back boiler£3,200
Upgrade to a system boiler (retaining hot water tanks)Back boiler£2,700
Upgrade to a combination boilerBack boiler£3,200

Want an exact price?

Use this boiler quote calculator.

Which New Boiler Will I Need?

As you can see in the chart above, your new boiler cost will vary quite a bit depending on the type of boiler you’re getting. So, let’s have a quick look at the most common condensing boiler types and help you figure out which one you’ll need.

The boiler types below will generally run on natural gas, LPG, or oil; if you’re interested in a biomass boiler, you can check out our guide to biomass boilers here.

Combi Boilers

Gas combi boilers are the most common boiler type these days. And there’s a good reason for it — they’re compact, efficient, and relatively inexpensive.

A combi boiler derives its name from the fact that it provide both heat and domestic hot water on demand. But this is also a shortcoming — since a combi boiler relies solely on mains water to supply your taps, you’re at the mercy of the mains water pressure. Meaning, if you’ve got robust hot water demand (i.e. 2-3 showers or taps that are frequently used at once), a combi boiler may not give you sufficient water pressure.

On the other hand, a gas combi boiler is a splendid choice for smaller households with moderate domestic water demand.

If your heating system doesn’t have a hot and/or cold water storage tank, then you’ve got a combi boiler fitted already. In this case — great news, replacing a combi boiler with a new combi boiler is typically the least expensive.

System Boilers

Unlike combi boilers, system boilers heat and store hot water in a special tank. This means they don’t provide hot water on demand like combi boilers do.

On the one hand, this is good news if you’ve got a larger home with lots of demand for hot water — with a system boiler, you needn’t worry about low water pressure.

On the other hand, the hot water cylinders system boilers rely on take up precious space. So, if you’ve got a smaller home, you may struggle to find enough room for this additional component.

Does your home have a storage tank for hot water but no cold water tank in the loft? In this case, you have a system boiler. Naturally, the cheapest way to go is to swap it for another system boiler.

However, if you fancy freeing up some space and throwing out the hot water cylinder, know that converting a system boiler to combi is an option — just be prepared to spend a few hundred quid more on the associated labour costs.

Note that you can also convert a back boiler to combi — you can read more about this conversion process, and associated costs, in our guide here.

Regular Boilers

Also known as heat-only or conventional boilers, these old workhorses are losing their popularity to the newer combi boilers.

But that’s not to say that a regular boiler is no longer useful. Quite the contrary — these boilers come with a hot water cylinder and a cold water storage tank, so they’re great at feeding large, thirsty households with copious amounts of hot water. And the pressure is fantastic.

That said, a heat only boiler requires lots of space. So, if you live in a smaller space, you may not be able to fit one of these appliances, and all the associated infrastructure in your home.

Do you have a hot water cylinder and a cold water feeder tank up in the loft? If you’ve answered “yes”, then you can rest assured that yours is a regular boiler. And, if it needs replacement, you’ve got 3 options:

  1. Swap for a new regular boiler and keep the tanks (least expensive)
  2. Replace with a system boiler and throw the cold feeder tank (more expensive)
  3. Convert your heat only boiler to a combi boiler and remove both the hot and cold water tanks (most expensive)

What kind of fuel does your boiler use?

Fixed price online with next day installation

Worcester boilers from as little as £1,965.

How Size Affects New Boiler Costs

Size is yet another factor that will dictate the cost of a new boiler (and when we say “size,” we mean the heating output in kW).

Now, there are no cut-and-dried formulae for calculating the exact output without accounting for a number of variables. However, here’s a quick table that summarises the 3 typical boiler size ranges:

Boiler SizeRadiatorsBathroomsProperty Type
24kW-27kW10 or fewer1Apartments, 1 & 2 bed houses
28kW-34kW10-152Medium size 2-4 bed homes
35kW-42kW15-2032+Larger Properties

Naturally, higher-capacity boilers cost more. How much more depends on a range of other factors (brand, model, type), so the cost differential is difficult to pinpoint. However, you can fill out this online calculator from Heatable and check out their fixed quotes for a number of different boiler types, brands, and sizes.

A New Location Will Add to Your New Boiler Cost

Moving your boiler to a new location will drive your new boiler costs up. 

That’s because you won’t be relocating the boiler alone; the Gas Safe heating engineer will have to move all the associated infrastructure, i.e. pipes and fittings, and find a new place for your flue to exit the residence. Worse yet, such a move may entail cutting out and replacing portions of your drywall. These tasks will require new materials and incur labour costs, which can set you back quite a bit depending on how long the job takes.

Now, it’s impossible for us to tell you precisely how much moving a boiler to a new location will add to your new boiler cost. You’d need a Gas Safe engineer to survey your property and give you an estimate. However, you can expect to spend at least £400-500 on top of your boiler installation cost.

New Boiler Cost — Boiler Installation Comparison

Of the 3 variables I listed above, 2 are pretty well beyond your control — you can’t change your property to suit a cheaper boiler. However, you can definitely save some money on the labour costs by choosing the right installer.

And that’s what we’ll discuss in this section. The comparison below will give you an idea of what to expect if you’re using an online installer like Heatable versus big names like British or Help-Link.

1. Heatable — The Fastest Way to Estimate Your New Boiler Cost

The good thing about Heatable, is you can log on, right now, and get a fixed price for a new boiler on-screen. There aren’t many companies offering that.

What kind of fuel does your boiler use?

Fixed price online with next day installation

Worcester boilers from as little as £1,965.

We went through their quote process, to see what the prices come out at. And to be fair, we’re happy with what we saw.

After some research, we realised so many of the boilers on offer are Worcester Bosch or Viessmann, and why these premium models were so cheap — it’s their volumes of work allowing for cheaper acquisition costs.

The new boiler we were looking for would’ve been suitable for a 3-bedroom flat. As you go through the quote process, you’ll see questions such as the type of flue, where the flue is located and how close it is to windows and doors.

For simplicity’s sake, we made sure our answers meant there’d be no additional work besides the boiler swap.

Once we completed the quote process, we were shown several boiler prices (about 10 in total). Being quite familiar with boilers, we knew that Heatable’s #1 pick, the Worcester Bosch Greenstar 4000, was the perfect new combi boiler for a 3-bedroom flat.

Worcester Bosch Greenstar 4000 combi boiler costs

And £2,040 is a great price for combi boiler installations, especially when you’re getting a Worcester. There was also the option for an equivalent boiler in compact form (one that would fit in a kitchen cupboard). That one was in a higher price range, but still a great deal.

Note — prices fluctuate often in today’s volatile market and vary by region. This means that you may not get the same price we did; you can get your own fixed-price quote by clicking here

As you scroll down, you’ll start hitting more expensive and higher-output boilers. Overall, though, boiler replacement costs from Heatable are about as cheap or cheaper than those of a local installer.

Have a look at the quote process — you can get a new boiler quote without inputting email addresses, phone numbers, and so on; it takes about 90 seconds.

2. British Gas — Reliable, But Not the Cheapest

British Gas are one of the biggest energy companies in the UK, and have a massive presence in the boiler replacement industry. They fit a tonne of boilers.

So, if you’ve already had a quote, there’s a good chance it’s come from British Gas. However, regardless of the national firm (e.ON, AA, and so on), it’s unlikely that this is the way to get the cheapest quote.

In fact, even Help-Link (a national boiler installation company mentioned below) are cheaper. They (and I quote) claim to save on average £1,081 when compared with a new boiler quote with British Gas.

New Boiler Installation Costs by British Gas

And, from my experience, you can expect to save a little more by using Heatable. Typically, we’d expect to see a saving of AT LEAST £1,000. The bigger and higher the price of the job, the more you’re likely to save.

Searching through a few online forums also reveals that our guess is correct. Here, someone had quotes ranging from £2,350, through to £7,000 from British Gas:

British gas new boiler cost

Now, remember — quotes will vary. Some include upgraded controls, boiler filters, and more, whilst others won’t. And, that’s important to take into account.

So, are British Gas too expensive? Like all national companies, they have large overheads for which to account. A cute penguin for TV adverts might get your name out there, but TV adverts aren’t cheap.

With a local installer, you can expect to pay much less than with a large national company. Same goes for online installers like Heatable.

3. Help-Link — Quick Quote, but on the Pricier Side

Another place you can get a quote for the cost of a new boiler is Help-Link.

We went through Help-Link’s online process to get boiler quotes, just as we did with Heatable. This isn’t a fixed quote, and we think that’s fair enough, sometimes a site visit is necessary.

Like the Heatable quote form, we picked all the simplest options, making this a straight boiler swap, rather than a full-on installation or central heating upgrade. And to be honest, I wasn’t that impressed.

New Boiler Installation Costs by Help-Link

Help-Link quoted us here over £2,000. And, whilst that might not seem like a big difference to the Heatable quote above, they’re quoting us for an Ideal Logic 24kw boiler.

Now, if you’ve read many of my other posts, you’ll know I rate high the Ideal Logic Plus range. But, as far as I can see, the Logic 24 HE isn’t the “Plus,” and that means you’ll only get a 2-year warranty. Typically, I’d be aiming for a 5-year warranty as a minimum.

You can grab up to 10 years from Heatable on a tonne of boilers, such as the Ideal Logic Plus, the Worcester Greenstar range, as well as others from Baxi, Vaillant and Potterton.

So, my opinion on the Help-Link boiler replacement is that it’s expensive. The new combi boiler cost for a Worcester equivalent was nearly £500 more, putting this boiler replacement price at over £2,500; essentially, it’s the same job as the one we got a quote for on Heatable.

Best Deals for the Lowest New Boiler Costs

Said it before, will say it again — your new boiler cost will depend on who you choose to install.

Put simply? Get quotes until your heart is content. You can read dozens of articles like this one, trawl forums, and more, but all you’ll get is an estimate.

The fact is, your new boiler cost will vary depending on the property, the area you live in, type of boiler, warranty, additional works, and more.

Get a FIXED New Boiler Cost Quote!

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Buy your new boiler online at a fixed price, with next day installation included.


Personally, I think the best deals come from Heatable.

Nationals just have too many overheads to cover. And inevitably, that’s going to be added to your boiler quote. As we’ve highlighted above, these nationals can be £1,000 more expensive on many occasions.

As cheap as local Gas Safe boiler fitters are, there’s no doubt that websites that offer an instant online quote facility, like Heatable, are hot on their heels. So, it’s worth comparing local boiler fitters, with a Heatable quote too.

Want an exact price?

Use this boiler quote calculator

Finally: Do You Need Boiler Replacement?

Our advice is: not every appliance needs replacing. Sometimes, a repair is a more cost-effective solution. Typically, you’ll want to start investigating a new boiler quote, if your boiler is out of warranty and there’s a repair bill looming of £500 or more.

Thanks to the cost of labour and materials, boilers are expensive to fix. And that’s not to mention the fact that there have been plenty of studies showing that new boilers that are A-Rated could save up to £305 per year on your energy bills.

Between zero repair costs and energy savings, a boiler replacement can quickly pay for itself.

Check out on-screen boiler installation prices using this quick form (no contact details needed, takes less than a minute of your time).

New Boiler Installation FAQ

Which is the best boiler to buy in 2022 for your home?

Worcester Bosch are renowned for being one of the most reliable brands in the UK heating space, offering the best customer service. Their Greenstar range including the 25i and 30i combi boilers are one of the best boilers to buy in 2022.

Is British Gas boiler installation expensive?

Compared to local installers, yes. The cost of boiler installation with large national companies is generally more higher than with local trades, or companies using an online business model such as Heatable. These online boiler installation companies can cut out salespeople and site visits, meaning they can supply and fit a new boiler much cheaper than they would be able to otherwise.

How long should a home boiler last?

You should expect your boiler to last 10-15 years. But it’s worth considering a replacement earlier if your boiler is out of warranty and you’re getting large and frequent repair bills.

How much does it cost to replace a boiler in your home?

Combi boiler installation for residential properties tends to start in the region of £1,600 for a small budget appliance. This can extend to £2,500 and beyond for properties needing a large new boiler, and an appliance with a long 10-year warranty.

How much does a new standalone boiler cost?

Assuming we’re talking about gas boilers, a standalone boiler — with no installation or extras — can cost anywhere from £500 to £2,500, depending on the type, model, and capacity. New gas combis start at £500 and go as high as £2,000, with £1,000 being the average for a mid-range model. System boilers are just a bit more expensive, typically topping out at £2,500 without installation.

Why does my boiler installation cost vary so much?

Installation costs hinge on a host of factors — your boiler type and model, your location, your property, whether or not you need to install the new boiler in a new place, and who you choose to install it for you. Simple swaps, where the new boiler goes into the exact same place as the old one, typically cost the least, whereas location changes and major alterations to infrastructure can quickly drive the costs up.

Likewise, using a large, national company to install your boiler rather than a local contractor or an online installer like Heatable may also cost you more. If you want to get a quick, fixed quote and use it as a benchmark against all the other estimates you solicit, I suggest you fill out this 90-second, anonymous survey from Heatable.

How long does it take to change a new boiler in your home?

Boiler installation costs

Expect a simple boiler installation to take 1-3 days. A straight swap without any upgrades would take 1 day. But, if the gas mains need to be upgraded, or you’re changing from a combi boiler or a system, the timescale could stretch to around 3 days.

Should I oversize my boiler?

No — oversizing your new boiler is a bad idea. Not only will you pay more for a higher-capacity model that you don’t really need, but your oversized boiler won’t operate efficiently. That’s because all that excess heat it generates will fail to dissipate through a smaller radiator network, and the return water will be too hot for the boiler to run on the most efficient, ‘condensing’ mode. So, you’ll be wasting heat, and consequently, overpaying for your energy bill. It’s far better to get a good understanding of what boiler size you need before you proceed to buy one.

Getting a Boiler for Free

There are strict criteria when it comes to getting a new boiler for free. Typically, it’s only pensioners that can get free boilers via the ECO (Energy Company Obligation) scheme. You can read our full guide to getting a free boiler here.

Conclusion on New Boiler Cost

Looking to get an idea of what a new boiler will cost?

Spend a minute of your time using this clickable form, and get your fixed price on the screen instantly.

And, if you have any questions, leave a comment below.

We’ll get back to you as soon as possible.

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  1. Fantastically comprehensive article here, thanks. I’d certainly argue that getting a boiler from a local company as opposed to one of the big British corporations can be a smart move – after all, all tradespeople must be trained to industry standards and therefore you won’t necessarily get a lower quality of service. Equally, you’ll avoid bureaucracy, and if you’re saved both time and money, there’s no reason not to entrust this expensive purchase into the hands of local plumbers.

  2. Hi,
    Does the 10 year guarantee cover parts & labour, are they installed by local installers who also undertake any repairs. Whoever are responsible for any repairs are they reliable to promptly do them as I.e British Gas would, or are you kept waiting.
    Regards J Waldron.

  3. Is the price the same if the existing boiler is in an internal cupboard with a flue running a few metres through a bedroom cupboard to the outside wall? The existing flue meets the regs, want to check if it can be reused for a different boiler. Thanks, Steve

  4. my boilers 20 years old but its passed 19 services with one to come in november.
    i want to change to a new boiler but British gas dont give out prices. i will go to the websites you suggest to get a price idea.
    another factor is the cost of the service plan. i know i can half it with british gas so i will save there.
    i have an ideal boiler which nhas been great. it has had a few repairs but its still going.
    thanks for your article.

    1. Hi Mark, glad you liked our article. IDEAL boilers are great. Worcester Bosch are too. I think it may be a price and brand affinity option for you. No?

  5. I’ve had a couple of quotes and one for a Potterton Titanic heat only and the other for a Worcester Greenstar 18Ri which I can’t see on your list of boilers. It is currently located in a kitchen cupboard and will be replaced there.
    I have a 5 bedroom, 1 bath and 3 en-suite but have a massive water tank.
    I would need smart thermostats.
    I’m not sure of the answers to some of your questions and wondered if I could talk to someone or whether you do site visits.
    Thank you

    1. Hi Leila,

      Unfortunately, we don’t do site visits. I think you should check the links in our article, BOXT has great service. We recommend them.

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